Mine exploder



Feb. 1, 1949. WALKER 2,460,322

MINE EXPLODER Filed May 26, 1945 Brooks Walker Patented Feb. 1, 1949 UNITED STATES PATENT QFFECE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 2 Claims.

The invention described herein may be manufactured and used by or for the Government for govermnental purposes, without the payment to me of any royalty thereon.

The present invention pertains to a novel mine exploder for use in military operations in which terrain evacuated by the enemy is suspected of being mined. The invention resides in the class of mine exploders propelled by a powerful vehicle such as a combat tank.

Many of these devices depend on the sheer weight of the parts for functioning the mines. The required weight for successful operation is at all times an impediment and is often in excess of the load that can be propelled by the available vehicles. Another type of mine exploder, known as the beater type, throws a number of chains:

or fiails rotatably against the ground. The objections to this type are the dust raised thereby, the erratic action of the chains, and the liability that mines buried close to the surface will be thrown and exploded against the vehicle or other nearby equipment.

The object of the present invention is to provide a comparatively simple and light-weight apparatus operating by forced impact against the ground, as distinguished from weight alone, and free of the objections to the beater type. Apparatus for these purposes may comprise a number of arms mounted across the vehicle on a horizontal axis and having their forward portions bent downwardly to engage the ground. A suitable trip mechanism may operate on each of the arms in a manner to lift them from the ground and then release them so that they may 1 come into engagement with the ground. A suit able pressure device, such as a spring, may operate on each arm to throw its forward portion against the ground when released by the trip mechanism, the impact being the sum of the net Weight of the arm and the force produced by this means. The arms are preferably resilient in order to pass over obstacles without breaking and to accommodate themselves to irregularities on the surface and in the hardness of the ground.

An illustrative embodiment of the invention is disclosed in the following description and in the accompanying drawing in which:

Figure l is a side elevation of a military vehicle equipped with the invention;

Figure 2 is a plan view thereof;

Figure 3 is a detailed longitudinal vertical section on line 3-3 of Figure 2, and

"Figures 4 and 5 are detail views illustrating modifications of features of construction. a

In Figure 1 is shown a military vehicle I such as a combat tank of the track-laying type. In the body of the vehicle, at its forward end, is journalled a shaft 2 which may be the sprocket shaft for the endless track 3. As is well known, a separate shaft 2 is mounted at each side of the vehicle, the two being capable of independent rotation, and such vehicles are commonly steered by stopping or slowing the transmission to the track at one side while the other is operated at a greater speed, to cause turning of the vehicle. On this shaft is mounted at each side of the vehicle a gear 4 for actuating the novel mechanism of this invention, as will presently 'be shown. Preferably, at each side of the vehicle an over-running clutch 2! is interposed between each of the gears 4 and shaft 2 for transmitting power from this shaft which produces forward motion of the vehicle. This facilitates turning of the vehicle and provides for operating the mine exploding means only during advancing or forward movements of the vehicle, as well as insuring that a mechanism to be described, driven commonly by the gears Ii, will be operated by that shaft 2 which has the greatest angular motion.

In the forwardend of the vehicle is provided a suitable frame and housing structure 5 for supporting a cam shaft 6 and an intermediate shaft I. The shaft I carries an intermediate gear 8 meshing with the gear 4 and also with a gear 9 on the shaft 6.

The structure 5 supports a series of tamping arms, as will presently be shown, and a suitable support for this purpose may consist of a series of sleeves I0 pivotally mounted on the structure 5 on a horizontal axis at H. The rear end of each sleeve is in the form of a stem l2 and is adapted to be drawn upward by a spring I 3 connecting it to an upper fixed point I 4 of the structure 5. The cam shaft 6 carries a series of cams I5 corresponding to and respectively engaging the stems I2.

In each sleeve I5 is inserted and fixed one end of a spring arm consisting preferably of spring steel having a round, square, hexagon or other suitable cross section. Each arm has its forward portion I'I bent downwardly at a substantial angle approximating a right angle. The free end I8 of each arm is positioned to come into ngagement with the ground at times and is suitably shaped for that purpose. 'As one cam I5 proceeds from the position shown in Figure 3, the portion I 8 is elevated from the'grou'nd by the increasing radius of the cam until the stem I2 trips or drops 'at the step [9 of the cam. At this time the spring l3, acting upon the stem l2 augments the force of gravity in accelerating the downward motion of the cam l6 and brings the point It forcibly against the ground.

As an example of suitable dimensions, each spring arm may have a diameter of one to oneand-a-half inches, and the ground contact point 3 may be about 6 feet in front of the vehicle.

The arms should be of such resiliency that theforward portions H are permitted to bend rearward on engaging the more common obstacles and thus pass over them. The resiliency may be increased, or brought to the desired degree, by reducing the cross section of the arm at the bend. The mechanism is preferably designed so that one tamp per arm for one rotation of the cam shaft 8 is obtained for each fiveinches of forward progress. This desirable objective may be and preferably is attained by a proper ratio in the gear train from the shaft 2, or by having steps I9 of the cams l displaced angularly with respect to each other in proper degree. Driving power required at any one time is minimized by having the steps IQ of successive cams IE on shaft 6 circumferentially spaced progressively in substantially like increments so as to trip the arms of the series successively in progression transversely of the vehicle as shown in Figure 4." The spacing of the arms should be about 6 inches center to center or '5 inches edge to edge. On this basis; the ground is struck by the arms at 5 inch intervals lengthwise and transversely of the path. Every mine 2.!) having a diameter or diagonal of 5 inches or more will be functioned, and it has been determined that practically all cnemymines are within this dimension.

The described actuating mechanism is merely illustrative, and .it will be evident that various types of cams and spring tripped toggles, ratchets,

pneumatic or hydraulic lifts and drives may be used. 'Iheimportant characteristic of the actuating mechanism is that the arms, when released, will be forced against the ground at a speed greater than that resulting from the mere weight of the arm. By such accelerating means the impact for a given weight is considerably greater than the impact by gravity alone, with the result that the total weight of the apparatus may be correspondingly reduced for a given desired impact.

The several arms 16 need not operate in unison in engaging the ground. It is preferred that the steps IQ of the cams l5 be spaced from one another in a cylindrical surface around the shaftB, or along a spiral, 'so that the arms will be operated at regular intervals with respect to each other and thereby make the driving load more nearly constant.

When the vehicle is traveling in territory which is not mined, it is desirable that arms it be elevated above the ground and held in inoperative positions. For this purpose, each of sleeves It may have associated therewith a lever 22 mounted to pivot at 23 on the structure 5. Each of these levers may have its lower end curved forwardly for engagement beneath a lug 24 carried by each of sleeves 58. If desired, each of levers 22 may have secured to its upper end a cable 26 which may extend rearwardly preferably within the vehicle where it may be secured for holding arms l6 elevated in the position shown in dotted lines in Figure 3.

this form a bracket is provided in the form of a split cylinder 21 having opposed mating flanges, one of which is indicated at 28. This bracket is adapted to be clamped in a fixed position about stem I 2 by suitable attaching elements such as rivets 29. On the upper side of cylinder 21 there is provided a radial bearing 38 which receives shaft ll and thus provides a pivotal support. The spring I3 is suitably attached to a bracket 25, fixed to stem I2, to add to the impact force of tamping arm or stem l2.

' In Figure 5 an alternate design is shown whereinuthe end of the tamping arm I6 is anchored'rigidly to a clamp 3| which may be rigidly attached to the vehicle or adjusted as shown by hand crank 32, screw 33, nut 34 and ball mounting 35. A connecting rod 36 engages cam 31 at its upper end and is pivoted to arm It at its lower end; A contractile spring 38 is connected between rod 36 and any suitable fixed point, as structure 5. In this way, arm I6 is flexed in tamping about bracket 31.

What 1 claim is:

i. In combination with a vehicle having a driven tractive member atv each side, mine explcder apparatus comprising a series of resilient tampingarms extendinglforwardly from the front of said vehicle and spaced transversely across the latter, each of said arms being pivotally supported at its rearward portion .on a horizontal axis by said front of said vehicle for vertical pivotal movement, each of said arms having a forward portion bent downwardly at a substantiai angle 'to theremainde'r of the respective arm, said forward portion terminating in a downwardly extending free end engage-able in a lowered position with 'the'grou'nd and simultaneously yieldable rearvt'ardl-y on fforward progression of the vehicle, means to accelerate downward movement of said forward portion of each of said arms when released from an elevated position in said vertical pivotal movement, and mechanism operably providing said vertical pivotal movement of said arms, said mechanism including a rotatable cam engaging said rearward portion of each of said arms .to alternately lift said forward portion thereof to .said elevated position and release it therefrom, whereby upon said release said down- .war iy extending free end will impact the ground with mine detonating force, and operating means connecting said cam with said driven tractive member at each side of said vehicle.

2. In combination with a vehicle having a driven tractive member at each side, mine exploder apparatus comprising a series of resilient tamping arms extending forwardly from the front of said vehicle and spaced transversely across the latter, each of said arms being pivotally supported at its rearward portion on a horizontal axis by said front of said vehicle for Vertical pivotal movement, each ofisaid forwardly extending arms having a forward portion bent downwardly :at a substantial angle approximately a right angle to the remainder of the respective arm, said forward portion terminating in a downwardly extending free end engageable in a lowered position with the ground and simultaneously resiliently yieldable rearwardly on forward progression of the vehicle, means to accelerate downward movement of said forward portion of each of said arms When-released from an elevated position in said vertical pivotal movement, whereby said downwardly extending free end will. impact the ground with mine detonating force, mechanism including rotatable cam members supported at the front of said vehicle and cooperable with said arms to provide said pivotal REFERENCES CITED mo m nt f th mtt id cam mb hav- The following references are of record in the ing steps respectively angularly displaced regufile Of this Patenti larly whereby said downwardly extending free 5 UNITED STATES PATENTS ends are lifted to said elevated pos1t1on and released therefrom at regular intervals relative to Number {Name Date each other, and operating means for said mecha- 350,331 Lubln 0 6 nism including an overrunning clutch connection 395,441 Taylor 1389 thereto with said driven tractive member on each 0 835,929 Bassett No 13, 1906 Side of i hi 74,2 5 Bass tt Dec. 17, 1907 BROOKS WALKER 1,174,803 Bathrick Mar. 7, 1916 1,458,655 Jahn June 12, 1923 1,505,572 McDonald Aug. 12, 1924 2,409,635 Langner Oct. 22, 1946 2,425,357 Walker Aug. 12, 1947 OTHER REFERENCES Popular Mechanics, September 1944, page 6. 

